TJA1021T/20.118 NXP Semiconductors, TJA1021T/20.118 Datasheet - Page 7

• Manufacturer Part Number: TJA1021T/20.118
• Manufacturer: NXP Semiconductors

Specifications of TJA1021T/20.118

• Operating Supply Voltage (min): 5.5V
• Operating Temperature Classification: Automotive
• Mounting: Surface Mount
• Pin Count: 8
• Lead Free Status / Rohs Status: Compliant

NXP Semiconductors
TJA1021_5
Product data sheet
7.5 Wake-up
7.6 Remote and local wake-up
7.7 Wake-up via mode transition
7.8 Wake-up source recognition
integrated filter to suppress bus line noise. The transmit data stream of the protocol
controller at the TXD input is converted by the transmitter into a bus signal with optimized
slew rate and wave shaping to minimize EME. The LIN bus output pin is pulled HIGH via
an internal slave termination resistor. For a master application an external resistor in
series with a diode should be connected between pin INH or V
on the other side (see
When in Sleep, Standby or Power-up mode, the TJA1021 enters Normal mode whenever
a HIGH level on pin SLP_N is maintained for a time of at least t
The TJA1021 switches to Sleep mode in case of a LOW-level on pin SLP_N, maintained
for a time of at least t
When V
Power-on mode. Though the TJA1021 is powered-up and INH is HIGH, both the
transmitter and receiver are still inactive. If SLP_N = 1 for t > t
Normal mode.
There are three ways to wake-up a TJA1021 which is in Sleep mode:
A falling edge at pin LIN followed by a LOW level maintained for a certain time period
(t
wake-up. It should be noted that the time period t
mode while TXD is HIGH, or in Sleep mode irrespective of the status of pin TXD.
A falling edge at pin WAKE_N followed by a LOW level maintained for a certain time
period (t
pull-up towards pin V
unused pin WAKE_N to pin V
After a local or remote wake-up, pin INH is activated (it goes HIGH) and the internal slave
termination resistor is switched on. The wake-up request is indicated by a LOW active
wake-up request signal on pin RXD to interrupt the microcontroller.
It is also possible to set pin INH HIGH with a mode transition towards Normal mode via pin
SLP_N. This is useful for applications with a continuously powered microcontroller.
The TJA1021 can distinguish between a local wake-up request on pin WAKE_N and a
remote wake-up request via a dominant bus state. 'A local wake-up request sets the
wake-up source flag. The wake-up source can be read on pin TXD in the Standby mode. If
an external pull-up resistor on pin TXD to the power supply voltage of the microcontroller
1. Remote wake-up via a dominant bus state of at least t
2. Local wake-up via a negative edge at pin WAKE_N
3. Mode change (pin SLP_N is HIGH) from Sleep mode to Normal mode
wake(dom)LIN
BAT
wake(dom)WAKE_N
exceeds the power-on-reset threshold voltage V
) and a rising edge at pin LIN respectively (see
BAT
gotosleep
Rev. 05 — 22 October 2009
Figure
) results in a local wake-up. The pin WAKE_N provides an internal
. In order to prevent EMI issues, it is recommended to connect an
.
BAT
6).
.
wake(dom)LIN
LIN 2.1/SAE J2602 transceiver
wake(dom)LIN
th(POR)H
Figure
is measured either in Normal
gotonorm
BAT
gotonorm
on one side and pin LIN
4) results in a remote
, the TJA1021 enters
, the TJA1021 enters
.
© NXP B.V. 2009. All rights reserved.
TJA1021
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